Shower base

ABSTRACT

The present invention provides a base structure for a shower, the shower having a water recirculation circuit, the base including a substantially planar floor and a reservoir, the reservoir including a first outlet for admitting water to be used by the recirculation circuit, and a second outlet for admitting water to be sent to waste, wherein in use where the passage of water to waste is obstructed, water contacting the floor runs into the reservoir to form a pool of sufficient depth to substantially cover the first outlet. Use of the structure may result in water and energy savings.

FIELD OF THE INVENTION

The present invention relates to a base structure for use in shower cubicles. In particular, the invention provides a shower base for use in showers that use water recirculation to save water.

BACKGROUND TO THE INVENTION

The issue of water conservation is becoming increasingly important given the effects of population and climate change on the world's water supplies. Significant volumes of water are wasted in the bathroom where many liters are sent to waste in the course of bathing and showering. While a shower is often considered to be less wasteful of water than a bath, this assumption may be valid only where the shower is of short duration. Many people enjoy the relaxing effects of a shower, and can often spend significant periods of time under running water. Many also attend to other tasks such as dental care, exfoliation, depilation and the like during showering. The extended time spent in the shower leads to wastage of significant amounts of water.

In an effort to limit the amount of water used in a shower, the prior art includes a number of shower systems including means for recirculation of water between the drain and the shower head. Typically, when in recirculation mode a valve positioned between the drain hole and sewer is closed (or the drain itself is closed), and a pump is used to extract water falling on the floor of the cubicle and direct it to the shower head for reapplication to the user. When the shower is in recirculation mode, input of mains water is not required and the user is able to remain under the shower for as long as desired without the further wastage of water.

While recirculation shower apparatuses can save water, many are still wasteful of the resource. One apparatus known in the art is the Kohler BodySpa system (Kohler Co, WI, U.S.A.). The Kohler system includes a tub in which the user stands, a recirculation pump that extracts water from the tub and directs it back to the user via a number of jets. While this system saves water when in recirculation mode, it requires a large volume of water in the system before the recirculation pump can be started. The tub must be filled to a level of around 150 mm, this equating to around 130 to 140 liters of water. A further problem with this and similar systems is that when in recirculation mode the user is forced to stand in a pool of water. This is unpleasant for the user, with the vast majority preferring the more familiar experience of a standard shower whereby water is drained away from the feet and lower legs. Relevant to the issue of water temperature the larger volume of recirculation water (having a commensurately large surface area) creates difficulties in maintaining a comfortable water temperature.

Other types of recirculation showers include a tank and a recirculation pump, these components being located under the floor of the shower base. In recirculation mode, water falling on the floor of the shower base runs into the drain but is diverted into a tank. A recirculation pump then extracts water from the tank, directing it to the shower head. This arrangement has a number of problems, one being that a shower base of increased height is necessary to accommodate components under the floor. It may therefore be difficult for persons having mobility issues to safely enter the shower. A high shower base is also aesthetically undesirable. Furthermore, having components under the floor makes maintenance and cleaning difficult.

Another problem with this design is that the recirculation water passes through the drain hole in the floor of the shower base. From the drain hole, the water then enters a separate tank for recirculation to the shower head. Users find the idea of being exposed to water that has entered a drain hole unsavory, and for good reason. Drain holes are known to be repositories for dirt and bacteria, this leading to the probable contamination of water passing through a drain. Given the closed nature of tank-based designs, it is also readily apparent that cleaning designs such as these also have the problem that the drain to waste is typically attached to the tank, this leading to access difficulties where the drain becomes blocked.

It is an aspect of the present invention to overcome or alleviate a problem of the prior art by providing a shower base that, when used in the context of a recirculation shower system, can reduce water requirements, is “slimline” and has easy access to components for the performance of hygienic maintenance.

A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

SUMMARY OF THE INVENTION

In one aspect the present invention provides a base structure for a shower having a water recirculation circuit, the base including a substantially planar floor and a reservoir, the reservoir including a first outlet for admitting water to be used by the recirculation circuit, and a second outlet for admitting water to be sent to waste, wherein where the passage of water to waste is obstructed, water contacting the floor runs into the reservoir to form a pool of sufficient depth to substantially cover the first outlet.

Applicant proposes that the use of a reservoir minimizes the amount of water required to be used in a recirculation shower apparatus. As will be understood, to start water moving through a recirculation circuit a minimum level of water must be available to the system. The minimum volume includes water necessary to fill all components of the circuit (for example pipes, valves, fittings, pumps etc), and also water necessary to ensure that the intake to the recirculation pump is covered with water. It is necessary to ensure that sufficient water is available to the intake side of the pump such that air, or at least a significant volume of air, is not drawn into the system. The presence of air can lead to cavitation in the pump causing complete cessation of water flow in the recirculation circuit. The presence of a reservoir about the first outlet means that only a small volume of water is necessary to cover the outlet, thereby decreasing the minimum volume of water required to run the shower in recirculation mode.

In operation, when the shower is in recirculation mode water from the shower head falls onto the floor of the shower base. The water then enters the reservoir where it pools because the drain outlet is closed. As the water level in the reservoir increases, the first outlet becomes submerged, ensuring that the pump intake is covered in water. Once the inlet is covered, the pump may then be safely operated. Thus, the reservoir acts to cover the intake with as small amount of water as possible such that the pump is able to still operate without sucking air.

In one form of the invention, the reservoir extends around at least a portion of the substantially planar floor. Alternatively, the substantially planar floor extends around the reservoir. In both these embodiments, to assist in the movement of water from the floor to the reservoir, the substantially planar surface is sloped such that water runs under the force of gravity into the reservoir.

Alternatively, to increase the efficiency of water collection from the floor the reservoir may extend distal to the first outlet. In one embodiment, the reservoir extends along one or more edges of the shower base. In this embodiment, the water may run into areas of the reservoir distal to the first outlet, but then further run to an area of the reservoir proximal to the first outlet.

The shape or dimensions of the reservoir can be altered according to the specific requirements of any given application. Of course, in order to minimize the volume of water used to operate the shower in recirculation mode, a reservoir of small volume is preferred. In one embodiment, the reservoir holds about 30 liters of water or less. In another embodiment, the reservoir holds about 15 liters of water or less. In yet a further embodiment the reservoir holds about 10 liters or less. When selecting an appropriate depth for the reservoir, consideration must be given to the depth required to cover the first inlet. In one embodiment, the depth is about 100 mm or less. In another embodiment the depth is about 50 mm or less. Where the reservoir is of variable depth, these figures refer to the deepest region of the reservoir.

The floor and reservoir may be arranged in any way relative to each other such that water contacting the floor is able to run into the reservoir. Typically, this is achieved by arranging the floor so that the surface is substantially continuous with the upper edge of the reservoir. In this arrangement, water runs under the force of gravity from the surface of the floor into the reservoir. This arrangement is facilitated by manufacturing the shower base in unitary form.

It will be understood that the term “a base structure for a shower” includes an arrangement whereby a shower is positioned above a bath tub, and water from the shower collects on the floor of the bath tub. In this form of the invention, the reservoir is included in the floor of the bath tub. The term also includes the floor of a shower room, typical of those found in public facilities such as gymnasiums, swimming pools and the like. In this form of the invention, the reservoir is included in the floor of the shower room.

In one form of the invention the first outlet is positioned in the reservoir such that water passes through the outlet in a non-vertical direction. Preferably, the first outlet is positioned such that water passes through the outlet in a substantially horizontal direction. This may be achieved by positioning the outlet on a substantially vertical wall of the reservoir. As discussed in the Background section, consumers are averse to being exposed to water that has entered a standard drain in the floor of a shower base. The use of a reservoir having an outlet on a substantially horizontal wall feeding the recirculation pump allows the user to assure them that the recirculating water enters only the inlet that feeds the recirculation pump and does not enter the drain. Furthermore, the horizontal exit of water provides the user confidence that water used for recirculation does not pool, as may be the case where the water exits vertically as occurs with a traditional drain hole in the floor of a shower base.

Users also dislike the tank-based designs of the prior art because of the inability to properly clean the tank. Accordingly, in another form of the invention, the reservoir is an open reservoir, as distinct from a reservoir that is closed, such as a tank.

It is emphasized that the water does not need to exit the reservoir exactly horizontally. So long as the water exits the reservoir in a non-vertical manner, the problem of water pooling will not result. The user will therefore not be left with the impression they are being exposed to contaminated water, such as that from a standard drain where water exits in a vertical direction.

It is further emphasized that the water does not need to maintain a horizontal flow for the entire distance between the first inlet and the recirculation pump. Indeed, in a preferred form of the invention there is a slight “fall” in the piping used to connect the pump and the reservoir such that water does not pool. Of course, the fall could be such that water runs to the pump (from which it subsequently drains), or indeed any other low point in the system.

The reservoir includes a second outlet to admit water to the drain, the outlet being operable between an open and closed state. In one form of the invention the second outlet is closed with a simple plug that is mounted on a spindle permanently affixed to the outlet. The plug is moveable along the spindle such that when it is distal to the outlet, water can enter the drain, and when in contact with the outlet the outlet is sealed. It is contemplated that the outlet can be moved from the open state to the closed state simply by the foot stepping on the plug. In one form of the invention the plug includes an overflow protection device such that the reservoir is not able to fill above a predetermined level. This is useful to prevent overflow of water from the shower base into the bathroom, and also for preventing overflow of water from the reservoir to the floor of the shower base. This latter use avoids the situation where the user is left standing in a pool of water if the mixer valve is closed too late after the shower is placed into recirculation mode, and excess water from the mains enters the system. One overflow protection device consists of an upright, hollow tube that extends upwards and through the plug, terminating above the plug at the maximum fill level of the reservoir. Thus, when the plug is closed and the water rises to the maximum fill level of the reservoir, any excess water entering the system runs down the hollow tube and to waste.

In another aspect the present invention provides a recirculation shower system including a shower base as described herein and a recirculation pump, the first outlet of the shower bases being connected to the recirculation pump such that in use water flows from the first outlet to the recirculation pump. In one form of the system, the water flows substantially horizontally from the first outlet of the shower base to the inlet of the recirculation pump. In another form of the invention the system is capable of operating on a volume of less than about 30 liters of water or less. In another embodiment, the system is capable of operating on about 15 liters of water or less. In yet a further embodiment the system is capable of operating on about 10 liters or less. Further savings in water usage will be obtained where small diameter pipes are used such that the minimum volume of water required for recirculation is lessened. In one form of the invention, pipes of a diameter of about 35 mm or less are used. In another form of the invention the pipes of a diameter of about 15 mm or less. A smaller diameter pipe used to convey water from the first inlet will also mean that a lower level of water is necessary in the reservoir to fully cover the inlet.

In another aspect, the present invention provides a kit of parts for assembly into a recirculation shower system as described herein, the kit including a base as described herein and a recirculation pump.

The present invention may provide advantages in respect to decreasing energy requirements for heating water used in showering. When in recirculation mode, further water is not admitted to the circuit, with water collected from the reservoir providing all water necessary to supply the shower head. In this embodiment of the invention, it is therefore not necessary to heat water from ambient temperature, to a temperature comfortable for showering. It will be appreciated that increased advantage may be gained where the ambient temperature is low (for example, 2 or 3 degrees Celsius) in which situation large amounts of energy are required to heat water up to a temperature comfortable for showering.

As an example of the energy savings that may be realized, it is accepted that 1 Calorie to energy is required to heat 1 gram of water by 1 degree Celsius. This relationship is applicable irrespective of the energy source used to heat the water. However, taking electric heating as an example, it is also accepted that 1 Calorie is equivalent to 0.001 162 222 Watt-hour.

The amount of energy in the shower water depends on the ambient (water inlet) temperature and the flow rate. Considering a conventional shower of the prior art, if the inlet water temperature is at 20 degrees Celsius and the shower water is at 40 degrees Celsius, this equates to a 20 Celsius temperature rise. At a flow rate of 10 lpm, this equates to 200,000 cal/min, or 232 Wh/min or 13.9 kWh energy consumption.

By comparison, a significantly lower amount of energy is required by a shower of the present invention when water recirculates via the reservoir. If the inlet water temperature (i.e. water from the reservoir is at 35 at Celsius, and the shower water is at 40 Celsius, it is only necessary for a heater positioned in the recirculation circuit to increase water temperature by 5 degrees Celsius. At a flow rate of 10 lpm, this equates to 50,000 cal/min, or 58 Wh/min or 3.5 kWh of energy consumption.

Thus, based upon the above calculations a shower of the present invention operating in recirculation mode provides a theoretical energy saving of around 75% where the ambient temperature is 20 degrees Celsius. If the inlet water temperature supplying a conventional shower was at 1 degree Celsius then the theoretical energy saving gained by a shower of the present invention would be around 87%. Thus, even greater energy savings are theoretically realized when operating a shower of the present invention in a cold climate.

The present invention will now be more fully described by reference to the non-limiting drawings.

IN THE FIGURES

FIG. 1. illustrates a plan view of the shower base of the invention.

FIG. 2 illustrates a cross-sectional view of the shower base shown in FIG. 1.

FIG. 3 illustrates a perspective view of a shower system according to the invention.

FIG. 4 is a schematic diagram of a shower system of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 illustrate a shower base structure according to the invention in plan view and cross-sectional view respectively. The base structure includes a substantially planar floor area 2 with a reservoir 4 abutting two sides of the floor. The reservoir 2 includes an outlet 6 to waste and an outlet 8 to the recirculation pump. While not apparent from the drawings, the floor area is sloped toward the reservoir. Furthermore, the floor of the reservoir is sloped toward the outlets 6 and 8 such that water falling on the floor runs to the nearest portion of the reservoir. Once in the reservoir, the water is then directed to a central region of the reservoir where outlets 6 and 8 are positioned.

FIG. 3 illustrates a corner-mounted shower system according to the invention including a substantially planar floor area 2 with a reservoir 4 abutting two sides of the floor area. The reservoir 2 includes an outlet 6 to waste and an outlet 8 to the recirculation. The central pillar 10 houses the recirculation pump and associated fittings, such as the shower head 12, and water mixer valve 14.

FIG. 4 is a schematic diagram of a shower system according to the invention. The system includes a substantially planar floor area 2 with a reservoir 4. The reservoir 4 includes an outlet 6 to waste and an outlet 8 to the recirculation pump 10. A check valve with relief mechanism 12 is included for isolation of the pump 10 from the outlet 8. The recirculation pump 10 is connected to the shower head 12, with an electric heater 14 disposed between the two. The heater 14 is actuated in response to the temperature sensor 16. Flow switches 18 are also included to provide flow information in the system, one being disposed downstream from the heater 14 such that the heater 14 is switched off if flow ceases. A second flow switch 18 is disposed between from the mains water entering by way of mixer valve 26 and pump 10 to provide information as to whether or not mains water is being admitted to the system. Hot and cold water is supplied via inlets 20 and 22 respectively, each inlet fitted with a water pressure reducing valve 24. A water mixer valve 26 is positioned between the water pressure reducing valves 24 and the shower head 12 allowing regulation of water pressure and temperature by the user. Vacuum breakers 28 are disposed between the intake side of the recirculation pump 10 and the mixer valve 26, the breakers actuating to prevent backflow of water into the mains supply. The system further includes a disinfection circuit having a disinfectant tank 30 with a fill cap 32, and an electrically operable valve 34 actuated by the switch 36. The pump is controlled in part by a microprocessor control unit 38 actuated by the switch 40.

When the user enters the shower cubicle, he opens mixer valve 26 and adjusts water temperature and pressure as desired. The shower is not in recirculation mode meaning that drain outlet 6 is open and the recirculation pump 10 is not operating. The shower operates like a regular shower in this mode with all water going to waste, and no water collecting in the reservoir 4. When the user wishes to commence recirculation mode he closes the drain outlet 6 and allows the reservoir to fill with water until the outlet 8 is covered with water. At that time, the user actuates switch 40 starting the recirculation pump 10. Water is then drawn from the reservoir 4 to the recirculation pump 10 via the outlet 8, and pumped to the shower head 12. Once recirculation flow is established, the user closes mixer valve 26 such that no mains water is being used, and all flow to the shower is from the reservoir 4. While in recirculation mode, the user may spend as long as desired under the shower without further wastage of water. If sufficient time elapses such that the water temperatures decreases to less than a predetermined value, this is detected by the sensor 16 and heater 14 is actuated until the water temperature returns to a comfortable level. At the conclusion of the session, the user will return from recirculation mode to normal mode by turning off the recirculation pump 10 using switch 40 and then opening the mixer valve 26 and opening the drain 6. Where it is desired to disinfect the recirculation circuit, the system is put into recirculation mode as described supra and the valve 34 actuated by the switch 36 to admit a disinfectant solution into the system.

Although the present invention has been described by reference to particular embodiments, it will be apparent to those skilled in the art that variations and modifications can be substituted therefore without departing from the principles and spirit of the invention. 

1-26. (canceled)
 27. A base structure for a shower, the shower having a water recirculation circuit, the base including a substantially planar floor and a reservoir, the reservoir including a first outlet for admitting water to be used by the recirculation circuit, and a second outlet for admitting water to be sent to waste, wherein in use where the passage of water to waste is obstructed, water contacting the floor runs into the reservoir to form a pool of sufficient depth to substantially cover the first outlet.
 28. A base structure according to claim 27 wherein the reservoir extends around at least a portion of the substantially planar floor.
 29. A base structure according to claim 27 wherein the substantially planar floor extends around the reservoir.
 30. A base structure according to claim 27 wherein the reservoir is capable of holding about 30 liters, or about 15 liters, or about 10 liters of water or less.
 31. A base structure according to claim 27 wherein the reservoir has a depth of about 100 mm or less, or about 50 mm or less.
 32. A base structure according to claim 27 wherein the reservoir is not a tank.
 33. A base structure according to claim 27 wherein the reservoir is not positioned partially or completely under the floor.
 34. A base structure according to claim 27 wherein the floor and reservoir are arranged relative to each other such that water contacting the floor is able to run into the reservoir.
 35. A base structure according to claim 34 wherein the floor is substantially continuous with the upper edge of the reservoir.
 36. A base structure according to claim 27 wherein the first outlet is positioned in the reservoir such that water passes through the outlet in a non-vertical direction or a substantially horizontal direction.
 37. A base structure according to claim 36 wherein the first outlet is positioned on a substantially vertical wall of the reservoir.
 38. A recirculation shower system including a shower base according to claim 27 and a recirculation pump, the first outlet of the shower base being connected to the recirculation pump such that in use water flows from the first outlet to the recirculation pump.
 39. A recirculation shower system according to claim 38 wherein in use water flows substantially horizontally from the first outlet of the shower base to the intake of the recirculation pump.
 40. A recirculation shower system according to claim 38 capable of operating on a volume of less than about 30 liters, or about 15 liters, or about 10 liters of water or less.
 41. A kit of parts for assembly into a recirculation shower system according to claim 12 including a base structure according to claim 27 and a recirculation pump. 